1. Field of the Invention
The present invention relates to a barcode reading apparatus and reading method for reading barcode information, and more particularly to a barcode reading apparatus and reading method for reading barcode information having a pattern represented in black and multiple patterns represented in colors other than black which are different from one another.
2. Description of the Related Art
There are mainly two kinds of barcode, that is, a one-dimensional barcode and a two-dimensional barcode. Each of them is basically configured in two colors of black and white though the amount of data to be handled is different, and data conversion is performed by reading and binarizing the barcode (symbol).
In many cases, the one-dimensional barcode is used for identifying an article, such as in the case of being read by a POS (Point of Sale) terminal installed at a register of a supermarket and the like.
The number of kinds and the amount of data which can be handled by the two-dimensional barcode is larger than that of the one-dimensional barcode. Therefore, for example, a barcode for the URL of a Website is created to reduce labor of an input operation at a small-sized terminal or apparatus, represented by a mobile phone, or a two-dimensional barcode is used to ensure traceability in manufacturing operations and in physical distribution. Furthermore, with the technological advance of small-sized cameras, a CMOS imager or a CCD camera has been mounted on various portable equipment recently. Thereby, provision of information with the use of the two-dimensional barcode is increasing, including provision by a mobile telephone, and it is often utilized to introduce the URL of a Website.
However, though the two-dimensional barcode is capable of providing a large amount of information for a user, the amount of information which can be provided by one barcode is limited. For example, a barcode that comprises the URL of the Website of a company which sells products can only show the URL of the first page of the Website, and it is necessary to prepare multiple barcodes and to secure sufficient space for displaying the multiple barcodes in order to provide multiple pieces of data such as the URL of a page that is used for product introductions that can be accessed from the first page of the Website, or such as the URL of a page shows a company profile.
Thus, the conventional barcode can represent only one single data irrespective of whether it is one-dimensional or two-dimensional.
Accordingly, a technique which enables one barcode to contain multiple pieces of information by assigning colors to each piece of information and by selectively radiating a light of the color that corresponds to the color coded information when the barcode is read is disclosed, for example, in Japanese Patent Laid-Open No. 1990-53194. In this technique, one barcode is represented in black, red, green and blue, and, by sequentially radiating red, green and blue lights, information having a pattern represented in the red color, information having a pattern represented in green and information having a pattern represented in blue are identifiably read from one barcode.
However, in the conventional technique as described above, information of a pattern represented in red, information of a pattern represented in green and information of a pattern represented in blue are only identifiably read from one barcode. Therefore, a user cannot selectively handle layered information, for example, information of a Website, that is, there remains the problem in which the user cannot extract only the information which he requires from the information that is contained in one barcode.